From 9e48858f7d36a6a3849f1d1b40c3bf5624b4ee7c Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Thu, 7 May 2009 19:26:19 +1000 Subject: security: rename ptrace_may_access => ptrace_access_check The ->ptrace_may_access() methods are named confusingly - the real ptrace_may_access() returns a bool, while these security checks have a retval convention. Rename it to ptrace_access_check, to reduce the confusion factor. [ Impact: cleanup, no code changed ] Signed-off-by: Ingo Molnar Signed-off-by: James Morris --- include/linux/security.h | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'include/linux') diff --git a/include/linux/security.h b/include/linux/security.h index 5eff459b383..145909165db 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -52,7 +52,7 @@ struct audit_krule; extern int cap_capable(struct task_struct *tsk, const struct cred *cred, int cap, int audit); extern int cap_settime(struct timespec *ts, struct timezone *tz); -extern int cap_ptrace_may_access(struct task_struct *child, unsigned int mode); +extern int cap_ptrace_access_check(struct task_struct *child, unsigned int mode); extern int cap_ptrace_traceme(struct task_struct *parent); extern int cap_capget(struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted); extern int cap_capset(struct cred *new, const struct cred *old, @@ -1209,7 +1209,7 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * @alter contains the flag indicating whether changes are to be made. * Return 0 if permission is granted. * - * @ptrace_may_access: + * @ptrace_access_check: * Check permission before allowing the current process to trace the * @child process. * Security modules may also want to perform a process tracing check @@ -1224,7 +1224,7 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * Check that the @parent process has sufficient permission to trace the * current process before allowing the current process to present itself * to the @parent process for tracing. - * The parent process will still have to undergo the ptrace_may_access + * The parent process will still have to undergo the ptrace_access_check * checks before it is allowed to trace this one. * @parent contains the task_struct structure for debugger process. * Return 0 if permission is granted. @@ -1336,7 +1336,7 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) struct security_operations { char name[SECURITY_NAME_MAX + 1]; - int (*ptrace_may_access) (struct task_struct *child, unsigned int mode); + int (*ptrace_access_check) (struct task_struct *child, unsigned int mode); int (*ptrace_traceme) (struct task_struct *parent); int (*capget) (struct task_struct *target, kernel_cap_t *effective, @@ -1617,7 +1617,7 @@ extern int security_module_enable(struct security_operations *ops); extern int register_security(struct security_operations *ops); /* Security operations */ -int security_ptrace_may_access(struct task_struct *child, unsigned int mode); +int security_ptrace_access_check(struct task_struct *child, unsigned int mode); int security_ptrace_traceme(struct task_struct *parent); int security_capget(struct task_struct *target, kernel_cap_t *effective, @@ -1798,10 +1798,10 @@ static inline int security_init(void) return 0; } -static inline int security_ptrace_may_access(struct task_struct *child, +static inline int security_ptrace_access_check(struct task_struct *child, unsigned int mode) { - return cap_ptrace_may_access(child, mode); + return cap_ptrace_access_check(child, mode); } static inline int security_ptrace_traceme(struct task_struct *parent) -- cgit v1.2.3 From ed5215a21460f63d6bdc118cb55a9e6d1b433f35 Mon Sep 17 00:00:00 2001 From: Thomas Liu Date: Thu, 9 Jul 2009 10:00:29 -0400 Subject: Move variable function in lsm_audit.h into SMACK private space Moved variable function in include/linux/lsm_audit.h into the smack_audit_data struct since it is never used outside of it. Also removed setting of function in the COMMON_AUDIT_DATA_INIT macro because that variable is now private to SMACK. Signed-off-by: Thomas Liu Acked-by: Eric Paris I-dont-see-any-problems-with-it: Casey Schaufler Signed-off-by: James Morris --- include/linux/lsm_audit.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/lsm_audit.h b/include/linux/lsm_audit.h index e461b2c3d71..68f7bce572b 100644 --- a/include/linux/lsm_audit.h +++ b/include/linux/lsm_audit.h @@ -66,11 +66,11 @@ struct common_audit_data { } key_struct; #endif } u; - const char *function; /* this union contains LSM specific data */ union { /* SMACK data */ struct smack_audit_data { + const char *function; char *subject; char *object; char *request; @@ -104,7 +104,7 @@ int ipv6_skb_to_auditdata(struct sk_buff *skb, /* Initialize an LSM audit data structure. */ #define COMMON_AUDIT_DATA_INIT(_d, _t) \ { memset((_d), 0, sizeof(struct common_audit_data)); \ - (_d)->type = LSM_AUDIT_DATA_##_t; (_d)->function = __func__; } + (_d)->type = LSM_AUDIT_DATA_##_t; } void common_lsm_audit(struct common_audit_data *a); -- cgit v1.2.3 From d4131ded4d4c1a5c1363ddd93ca104ed97dd0458 Mon Sep 17 00:00:00 2001 From: Thomas Liu Date: Thu, 9 Jul 2009 10:00:30 -0400 Subject: security: Make lsm_priv union in lsm_audit.h anonymous Made the lsm_priv union in include/linux/lsm_audit.h anonymous. Signed-off-by: Thomas Liu Acked-by: Eric Paris Signed-off-by: James Morris --- include/linux/lsm_audit.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/lsm_audit.h b/include/linux/lsm_audit.h index 68f7bce572b..40d1b84f2a3 100644 --- a/include/linux/lsm_audit.h +++ b/include/linux/lsm_audit.h @@ -86,7 +86,7 @@ struct common_audit_data { struct av_decision *avd; int result; } selinux_audit_data; - } lsm_priv; + }; /* these callback will be implemented by a specific LSM */ void (*lsm_pre_audit)(struct audit_buffer *, void *); void (*lsm_post_audit)(struct audit_buffer *, void *); -- cgit v1.2.3 From 65c3f0a2d0f72d210c879e4974c2d222b7951321 Mon Sep 17 00:00:00 2001 From: Thomas Liu Date: Thu, 9 Jul 2009 10:00:31 -0400 Subject: security: Wrap SMACK and SELINUX audit data structs in ifdefs Wrapped the smack_audit_data and selinux_audit_data structs in include/linux/lsm_audit.h in ifdefs so that the union will always be the correct size. Signed-off-by: Thomas Liu Acked-by: Eric Paris Signed-off-by: James Morris --- include/linux/lsm_audit.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux') diff --git a/include/linux/lsm_audit.h b/include/linux/lsm_audit.h index 40d1b84f2a3..a5514a3a4f1 100644 --- a/include/linux/lsm_audit.h +++ b/include/linux/lsm_audit.h @@ -68,6 +68,7 @@ struct common_audit_data { } u; /* this union contains LSM specific data */ union { +#ifdef CONFIG_SECURITY_SMACK /* SMACK data */ struct smack_audit_data { const char *function; @@ -76,6 +77,8 @@ struct common_audit_data { char *request; int result; } smack_audit_data; +#endif +#ifdef CONFIG_SECURITY_SELINUX /* SELinux data */ struct { u32 ssid; @@ -86,6 +89,7 @@ struct common_audit_data { struct av_decision *avd; int result; } selinux_audit_data; +#endif }; /* these callback will be implemented by a specific LSM */ void (*lsm_pre_audit)(struct audit_buffer *, void *); -- cgit v1.2.3 From b3a633c8527ef155b1a4e22e8f5abc58f7af54c9 Mon Sep 17 00:00:00 2001 From: Julien Tinnes Date: Fri, 10 Jul 2009 10:46:30 -0700 Subject: personality handling: fix PER_CLEAR_ON_SETID for security reasons We have found that the current PER_CLEAR_ON_SETID mask on Linux doesn't include neither ADDR_COMPAT_LAYOUT, nor MMAP_PAGE_ZERO. The current mask is READ_IMPLIES_EXEC|ADDR_NO_RANDOMIZE. We believe it is important to add MMAP_PAGE_ZERO, because by using this personality it is possible to have the first page mapped inside a process running as setuid root. This could be used in those scenarios: - Exploiting a NULL pointer dereference issue in a setuid root binary - Bypassing the mmap_min_addr restrictions of the Linux kernel: by running a setuid binary that would drop privileges before giving us control back (for instance by loading a user-supplied library), we could get the first page mapped in a process we control. By further using mremap and mprotect on this mapping, we can then completely bypass the mmap_min_addr restrictions. Less importantly, we believe ADDR_COMPAT_LAYOUT should also be added since on x86 32bits it will in practice disable most of the address space layout randomization (only the stack will remain randomized). Signed-off-by: Julien Tinnes Signed-off-by: Tavis Ormandy Acked-by: Christoph Hellwig Acked-by: Kees Cook Signed-off-by: James Morris --- include/linux/personality.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/personality.h b/include/linux/personality.h index a84e9ff9b27..b7f578dac54 100644 --- a/include/linux/personality.h +++ b/include/linux/personality.h @@ -40,7 +40,11 @@ enum { * Security-relevant compatibility flags that must be * cleared upon setuid or setgid exec: */ -#define PER_CLEAR_ON_SETID (READ_IMPLIES_EXEC|ADDR_NO_RANDOMIZE) +#define PER_CLEAR_ON_SETID \ + (READ_IMPLIES_EXEC | \ + ADDR_NO_RANDOMIZE | \ + ADDR_COMPAT_LAYOUT | \ + MMAP_PAGE_ZERO) /* * Personality types. -- cgit v1.2.3 From 5bb459bb45d1ad3c177485dcf0af01580aa31125 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Fri, 10 Jul 2009 03:48:23 +0200 Subject: kernel: rename is_single_threaded(task) to current_is_single_threaded(void) - is_single_threaded(task) is not safe unless task == current, we can't use task->signal or task->mm. - it doesn't make sense unless task == current, the task can fork right after the check. Rename it to current_is_single_threaded() and kill the argument. Signed-off-by: Oleg Nesterov Acked-by: David Howells Signed-off-by: James Morris --- include/linux/sched.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/sched.h b/include/linux/sched.h index 16a982e389f..0839a2c9b95 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2075,7 +2075,7 @@ static inline unsigned long wait_task_inactive(struct task_struct *p, #define for_each_process(p) \ for (p = &init_task ; (p = next_task(p)) != &init_task ; ) -extern bool is_single_threaded(struct task_struct *); +extern bool current_is_single_threaded(void); /* * Careful: do_each_thread/while_each_thread is a double loop so -- cgit v1.2.3 From 1c388ad054fb1ead3dc354b1719570b99e464135 Mon Sep 17 00:00:00 2001 From: Paul Menage Date: Fri, 17 Jul 2009 16:16:18 -0700 Subject: include/linux/cred.h: work around gcc-4.2.4 warning in get_cred() With gcc 4.2.4 (building UML) I get the warning include/linux/cred.h: In function 'get_cred': include/linux/cred.h:189: warning: passing argument 1 of 'get_new_cred' discards qualifiers from pointer target type Inserting an additional local variable appears to keep the compiler happy, although it's not clear to me why this should be needed. Signed-off-by: Paul Menage Signed-off-by: Andrew Morton Acked-by: David Howells Signed-off-by: James Morris --- include/linux/cred.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/cred.h b/include/linux/cred.h index 4fa99969631..b3c76e815d6 100644 --- a/include/linux/cred.h +++ b/include/linux/cred.h @@ -186,7 +186,8 @@ static inline struct cred *get_new_cred(struct cred *cred) */ static inline const struct cred *get_cred(const struct cred *cred) { - return get_new_cred((struct cred *) cred); + struct cred *nonconst_cred = (struct cred *) cred; + return get_new_cred(nonconst_cred); } /** -- cgit v1.2.3 From 7c73875e7dda627040b12c19b01db634fa7f0fd1 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Fri, 31 Jul 2009 12:53:58 -0400 Subject: Capabilities: move cap_file_mmap to commoncap.c Currently we duplicate the mmap_min_addr test in cap_file_mmap and in security_file_mmap if !CONFIG_SECURITY. This patch moves cap_file_mmap into commoncap.c and then calls that function directly from security_file_mmap ifndef CONFIG_SECURITY like all of the other capability checks are done. Signed-off-by: Eric Paris Acked-by: Serge Hallyn Signed-off-by: James Morris --- include/linux/security.h | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/security.h b/include/linux/security.h index 145909165db..963a48fc300 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -66,6 +66,9 @@ extern int cap_inode_setxattr(struct dentry *dentry, const char *name, extern int cap_inode_removexattr(struct dentry *dentry, const char *name); extern int cap_inode_need_killpriv(struct dentry *dentry); extern int cap_inode_killpriv(struct dentry *dentry); +extern int cap_file_mmap(struct file *file, unsigned long reqprot, + unsigned long prot, unsigned long flags, + unsigned long addr, unsigned long addr_only); extern int cap_task_fix_setuid(struct cred *new, const struct cred *old, int flags); extern int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, unsigned long arg5); @@ -2197,9 +2200,7 @@ static inline int security_file_mmap(struct file *file, unsigned long reqprot, unsigned long addr, unsigned long addr_only) { - if ((addr < mmap_min_addr) && !capable(CAP_SYS_RAWIO)) - return -EACCES; - return 0; + return cap_file_mmap(file, reqprot, prot, flags, addr, addr_only); } static inline int security_file_mprotect(struct vm_area_struct *vma, -- cgit v1.2.3 From a2551df7ec568d87793d2eea4ca744e86318f205 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Fri, 31 Jul 2009 12:54:11 -0400 Subject: Security/SELinux: seperate lsm specific mmap_min_addr Currently SELinux enforcement of controls on the ability to map low memory is determined by the mmap_min_addr tunable. This patch causes SELinux to ignore the tunable and instead use a seperate Kconfig option specific to how much space the LSM should protect. The tunable will now only control the need for CAP_SYS_RAWIO and SELinux permissions will always protect the amount of low memory designated by CONFIG_LSM_MMAP_MIN_ADDR. This allows users who need to disable the mmap_min_addr controls (usual reason being they run WINE as a non-root user) to do so and still have SELinux controls preventing confined domains (like a web server) from being able to map some area of low memory. Signed-off-by: Eric Paris Signed-off-by: James Morris --- include/linux/mm.h | 15 --------------- include/linux/security.h | 17 +++++++++++++++++ 2 files changed, 17 insertions(+), 15 deletions(-) (limited to 'include/linux') diff --git a/include/linux/mm.h b/include/linux/mm.h index ba3a7cb1eaa..9a72cc78e6b 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -34,8 +34,6 @@ extern int sysctl_legacy_va_layout; #define sysctl_legacy_va_layout 0 #endif -extern unsigned long mmap_min_addr; - #include #include #include @@ -574,19 +572,6 @@ static inline void set_page_links(struct page *page, enum zone_type zone, set_page_section(page, pfn_to_section_nr(pfn)); } -/* - * If a hint addr is less than mmap_min_addr change hint to be as - * low as possible but still greater than mmap_min_addr - */ -static inline unsigned long round_hint_to_min(unsigned long hint) -{ - hint &= PAGE_MASK; - if (((void *)hint != NULL) && - (hint < mmap_min_addr)) - return PAGE_ALIGN(mmap_min_addr); - return hint; -} - /* * Some inline functions in vmstat.h depend on page_zone() */ diff --git a/include/linux/security.h b/include/linux/security.h index 963a48fc300..7b431155e39 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -28,6 +28,7 @@ #include #include #include +#include /* PAGE_ALIGN */ #include #include #include @@ -95,6 +96,7 @@ extern int cap_netlink_send(struct sock *sk, struct sk_buff *skb); extern int cap_netlink_recv(struct sk_buff *skb, int cap); extern unsigned long mmap_min_addr; +extern unsigned long dac_mmap_min_addr; /* * Values used in the task_security_ops calls */ @@ -147,6 +149,21 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) opts->num_mnt_opts = 0; } +/* + * If a hint addr is less than mmap_min_addr change hint to be as + * low as possible but still greater than mmap_min_addr + */ +static inline unsigned long round_hint_to_min(unsigned long hint) +{ + hint &= PAGE_MASK; + if (((void *)hint != NULL) && + (hint < mmap_min_addr)) + return PAGE_ALIGN(mmap_min_addr); + return hint; +} + +extern int mmap_min_addr_handler(struct ctl_table *table, int write, struct file *filp, + void __user *buffer, size_t *lenp, loff_t *ppos); /** * struct security_operations - main security structure * -- cgit v1.2.3 From 47d439e9fb8a81a90022cfa785bf1c36c4e2aff6 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Fri, 7 Aug 2009 14:53:57 -0400 Subject: security: define round_hint_to_min in !CONFIG_SECURITY Fix the header files to define round_hint_to_min() and to define mmap_min_addr_handler() in the !CONFIG_SECURITY case. Built and tested with !CONFIG_SECURITY Signed-off-by: Eric Paris Signed-off-by: James Morris --- include/linux/security.h | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) (limited to 'include/linux') diff --git a/include/linux/security.h b/include/linux/security.h index 7b431155e39..57ead99d259 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -121,6 +121,21 @@ struct request_sock; #define LSM_UNSAFE_PTRACE 2 #define LSM_UNSAFE_PTRACE_CAP 4 +/* + * If a hint addr is less than mmap_min_addr change hint to be as + * low as possible but still greater than mmap_min_addr + */ +static inline unsigned long round_hint_to_min(unsigned long hint) +{ + hint &= PAGE_MASK; + if (((void *)hint != NULL) && + (hint < mmap_min_addr)) + return PAGE_ALIGN(mmap_min_addr); + return hint; +} +extern int mmap_min_addr_handler(struct ctl_table *table, int write, struct file *filp, + void __user *buffer, size_t *lenp, loff_t *ppos); + #ifdef CONFIG_SECURITY struct security_mnt_opts { @@ -149,21 +164,6 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) opts->num_mnt_opts = 0; } -/* - * If a hint addr is less than mmap_min_addr change hint to be as - * low as possible but still greater than mmap_min_addr - */ -static inline unsigned long round_hint_to_min(unsigned long hint) -{ - hint &= PAGE_MASK; - if (((void *)hint != NULL) && - (hint < mmap_min_addr)) - return PAGE_ALIGN(mmap_min_addr); - return hint; -} - -extern int mmap_min_addr_handler(struct ctl_table *table, int write, struct file *filp, - void __user *buffer, size_t *lenp, loff_t *ppos); /** * struct security_operations - main security structure * -- cgit v1.2.3 From 9188499cdb117d86a1ea6b04374095b098d56936 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Thu, 13 Aug 2009 09:44:57 -0400 Subject: security: introducing security_request_module Calling request_module() will trigger a userspace upcall which will load a new module into the kernel. This can be a dangerous event if the process able to trigger request_module() is able to control either the modprobe binary or the module binary. This patch adds a new security hook to request_module() which can be used by an LSM to control a processes ability to call request_module(). Signed-off-by: Eric Paris Acked-by: Serge Hallyn Signed-off-by: James Morris --- include/linux/security.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'include/linux') diff --git a/include/linux/security.h b/include/linux/security.h index 57ead99d259..1e3dd86eea9 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -678,6 +678,9 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * @inode points to the inode to use as a reference. * The current task must be the one that nominated @inode. * Return 0 if successful. + * @kernel_module_request: + * Ability to trigger the kernel to automatically upcall to userspace for + * userspace to load a kernel module with the given name. * @task_setuid: * Check permission before setting one or more of the user identity * attributes of the current process. The @flags parameter indicates @@ -1489,6 +1492,7 @@ struct security_operations { void (*cred_commit)(struct cred *new, const struct cred *old); int (*kernel_act_as)(struct cred *new, u32 secid); int (*kernel_create_files_as)(struct cred *new, struct inode *inode); + int (*kernel_module_request)(void); int (*task_setuid) (uid_t id0, uid_t id1, uid_t id2, int flags); int (*task_fix_setuid) (struct cred *new, const struct cred *old, int flags); @@ -1741,6 +1745,7 @@ int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp); void security_commit_creds(struct cred *new, const struct cred *old); int security_kernel_act_as(struct cred *new, u32 secid); int security_kernel_create_files_as(struct cred *new, struct inode *inode); +int security_kernel_module_request(void); int security_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags); int security_task_fix_setuid(struct cred *new, const struct cred *old, int flags); @@ -2292,6 +2297,11 @@ static inline int security_kernel_create_files_as(struct cred *cred, return 0; } +static inline int security_kernel_module_request(void) +{ + return 0; +} + static inline int security_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags) { -- cgit v1.2.3 From f322abf83feddc3c37c3a91794e0c5aece4af18e Mon Sep 17 00:00:00 2001 From: James Morris Date: Fri, 14 Aug 2009 11:19:29 +1000 Subject: security: update documentation for security_request_module Update documentation for security_request_module to indicate return value, as suggested by Serge Hallyn. Signed-off-by: James Morris --- include/linux/security.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/security.h b/include/linux/security.h index 1e3dd86eea9..a16d6b7c4eb 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -681,6 +681,7 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * @kernel_module_request: * Ability to trigger the kernel to automatically upcall to userspace for * userspace to load a kernel module with the given name. + * Return 0 if successful. * @task_setuid: * Check permission before setting one or more of the user identity * attributes of the current process. The @flags parameter indicates -- cgit v1.2.3 From 2bf49690325b62480a42f7afed5e9f164173c570 Mon Sep 17 00:00:00 2001 From: Thomas Liu Date: Tue, 14 Jul 2009 12:14:09 -0400 Subject: SELinux: Convert avc_audit to use lsm_audit.h Convert avc_audit in security/selinux/avc.c to use lsm_audit.h, for better maintainability. - changed selinux to use common_audit_data instead of avc_audit_data - eliminated code in avc.c and used code from lsm_audit.h instead. Had to add a LSM_AUDIT_NO_AUDIT to lsm_audit.h so that avc_audit can call common_lsm_audit and do the pre and post callbacks without doing the actual dump. This makes it so that the patched version behaves the same way as the unpatched version. Also added a denied field to the selinux_audit_data private space, once again to make it so that the patched version behaves like the unpatched. I've tested and confirmed that AVCs look the same before and after this patch. Signed-off-by: Thomas Liu Acked-by: Stephen Smalley Signed-off-by: James Morris --- include/linux/lsm_audit.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/lsm_audit.h b/include/linux/lsm_audit.h index a5514a3a4f1..190c3785487 100644 --- a/include/linux/lsm_audit.h +++ b/include/linux/lsm_audit.h @@ -33,6 +33,7 @@ struct common_audit_data { #define LSM_AUDIT_DATA_IPC 4 #define LSM_AUDIT_DATA_TASK 5 #define LSM_AUDIT_DATA_KEY 6 +#define LSM_AUDIT_NO_AUDIT 7 struct task_struct *tsk; union { struct { @@ -86,6 +87,7 @@ struct common_audit_data { u16 tclass; u32 requested; u32 audited; + u32 denied; struct av_decision *avd; int result; } selinux_audit_data; -- cgit v1.2.3 From 2b980dbd77d229eb60588802162c9659726b11f4 Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Fri, 28 Aug 2009 18:12:43 -0400 Subject: lsm: Add hooks to the TUN driver The TUN driver lacks any LSM hooks which makes it difficult for LSM modules, such as SELinux, to enforce access controls on network traffic generated by TUN users; this is particularly problematic for virtualization apps such as QEMU and KVM. This patch adds three new LSM hooks designed to control the creation and attachment of TUN devices, the hooks are: * security_tun_dev_create() Provides access control for the creation of new TUN devices * security_tun_dev_post_create() Provides the ability to create the necessary socket LSM state for newly created TUN devices * security_tun_dev_attach() Provides access control for attaching to existing, persistent TUN devices and the ability to update the TUN device's socket LSM state as necessary Signed-off-by: Paul Moore Acked-by: Eric Paris Acked-by: Serge Hallyn Acked-by: David S. Miller Signed-off-by: James Morris --- include/linux/security.h | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) (limited to 'include/linux') diff --git a/include/linux/security.h b/include/linux/security.h index a16d6b7c4eb..40ba39ea68c 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -998,6 +998,17 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * Sets the connection's peersid to the secmark on skb. * @req_classify_flow: * Sets the flow's sid to the openreq sid. + * @tun_dev_create: + * Check permissions prior to creating a new TUN device. + * @tun_dev_post_create: + * This hook allows a module to update or allocate a per-socket security + * structure. + * @sk contains the newly created sock structure. + * @tun_dev_attach: + * Check permissions prior to attaching to a persistent TUN device. This + * hook can also be used by the module to update any security state + * associated with the TUN device's sock structure. + * @sk contains the existing sock structure. * * Security hooks for XFRM operations. * @@ -1597,6 +1608,9 @@ struct security_operations { void (*inet_csk_clone) (struct sock *newsk, const struct request_sock *req); void (*inet_conn_established) (struct sock *sk, struct sk_buff *skb); void (*req_classify_flow) (const struct request_sock *req, struct flowi *fl); + int (*tun_dev_create)(void); + void (*tun_dev_post_create)(struct sock *sk); + int (*tun_dev_attach)(struct sock *sk); #endif /* CONFIG_SECURITY_NETWORK */ #ifdef CONFIG_SECURITY_NETWORK_XFRM @@ -2586,6 +2600,9 @@ void security_inet_csk_clone(struct sock *newsk, const struct request_sock *req); void security_inet_conn_established(struct sock *sk, struct sk_buff *skb); +int security_tun_dev_create(void); +void security_tun_dev_post_create(struct sock *sk); +int security_tun_dev_attach(struct sock *sk); #else /* CONFIG_SECURITY_NETWORK */ static inline int security_unix_stream_connect(struct socket *sock, @@ -2736,6 +2753,20 @@ static inline void security_inet_conn_established(struct sock *sk, struct sk_buff *skb) { } + +static inline int security_tun_dev_create(void) +{ + return 0; +} + +static inline void security_tun_dev_post_create(struct sock *sk) +{ +} + +static inline int security_tun_dev_attach(struct sock *sk) +{ + return 0; +} #endif /* CONFIG_SECURITY_NETWORK */ #ifdef CONFIG_SECURITY_NETWORK_XFRM -- cgit v1.2.3 From e0e817392b9acf2c98d3be80c233dddb1b52003d Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 2 Sep 2009 09:13:40 +0100 Subject: CRED: Add some configurable debugging [try #6] Add a config option (CONFIG_DEBUG_CREDENTIALS) to turn on some debug checking for credential management. The additional code keeps track of the number of pointers from task_structs to any given cred struct, and checks to see that this number never exceeds the usage count of the cred struct (which includes all references, not just those from task_structs). Furthermore, if SELinux is enabled, the code also checks that the security pointer in the cred struct is never seen to be invalid. This attempts to catch the bug whereby inode_has_perm() faults in an nfsd kernel thread on seeing cred->security be a NULL pointer (it appears that the credential struct has been previously released): http://www.kerneloops.org/oops.php?number=252883 Signed-off-by: David Howells Signed-off-by: James Morris --- include/linux/cred.h | 65 +++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 64 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/cred.h b/include/linux/cred.h index b3c76e815d6..85439abdbc8 100644 --- a/include/linux/cred.h +++ b/include/linux/cred.h @@ -114,6 +114,13 @@ struct thread_group_cred { */ struct cred { atomic_t usage; +#ifdef CONFIG_DEBUG_CREDENTIALS + atomic_t subscribers; /* number of processes subscribed */ + void *put_addr; + unsigned magic; +#define CRED_MAGIC 0x43736564 +#define CRED_MAGIC_DEAD 0x44656144 +#endif uid_t uid; /* real UID of the task */ gid_t gid; /* real GID of the task */ uid_t suid; /* saved UID of the task */ @@ -143,6 +150,7 @@ struct cred { }; extern void __put_cred(struct cred *); +extern void exit_creds(struct task_struct *); extern int copy_creds(struct task_struct *, unsigned long); extern struct cred *prepare_creds(void); extern struct cred *prepare_exec_creds(void); @@ -158,6 +166,60 @@ extern int set_security_override_from_ctx(struct cred *, const char *); extern int set_create_files_as(struct cred *, struct inode *); extern void __init cred_init(void); +/* + * check for validity of credentials + */ +#ifdef CONFIG_DEBUG_CREDENTIALS +extern void __invalid_creds(const struct cred *, const char *, unsigned); +extern void __validate_process_creds(struct task_struct *, + const char *, unsigned); + +static inline bool creds_are_invalid(const struct cred *cred) +{ + if (cred->magic != CRED_MAGIC) + return true; + if (atomic_read(&cred->usage) < atomic_read(&cred->subscribers)) + return true; +#ifdef CONFIG_SECURITY_SELINUX + if ((unsigned long) cred->security < PAGE_SIZE) + return true; + if ((*(u32*)cred->security & 0xffffff00) == + (POISON_FREE << 24 | POISON_FREE << 16 | POISON_FREE << 8)) + return true; +#endif + return false; +} + +static inline void __validate_creds(const struct cred *cred, + const char *file, unsigned line) +{ + if (unlikely(creds_are_invalid(cred))) + __invalid_creds(cred, file, line); +} + +#define validate_creds(cred) \ +do { \ + __validate_creds((cred), __FILE__, __LINE__); \ +} while(0) + +#define validate_process_creds() \ +do { \ + __validate_process_creds(current, __FILE__, __LINE__); \ +} while(0) + +extern void validate_creds_for_do_exit(struct task_struct *); +#else +static inline void validate_creds(const struct cred *cred) +{ +} +static inline void validate_creds_for_do_exit(struct task_struct *tsk) +{ +} +static inline void validate_process_creds(void) +{ +} +#endif + /** * get_new_cred - Get a reference on a new set of credentials * @cred: The new credentials to reference @@ -187,6 +249,7 @@ static inline struct cred *get_new_cred(struct cred *cred) static inline const struct cred *get_cred(const struct cred *cred) { struct cred *nonconst_cred = (struct cred *) cred; + validate_creds(cred); return get_new_cred(nonconst_cred); } @@ -205,7 +268,7 @@ static inline void put_cred(const struct cred *_cred) { struct cred *cred = (struct cred *) _cred; - BUG_ON(atomic_read(&(cred)->usage) <= 0); + validate_creds(cred); if (atomic_dec_and_test(&(cred)->usage)) __put_cred(cred); } -- cgit v1.2.3 From 5d135440faf7db8d566de0c6fab36b16cf9cfc3b Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 2 Sep 2009 09:14:00 +0100 Subject: KEYS: Add garbage collection for dead, revoked and expired keys. [try #6] Add garbage collection for dead, revoked and expired keys. This involved erasing all links to such keys from keyrings that point to them. At that point, the key will be deleted in the normal manner. Keyrings from which garbage collection occurs are shrunk and their quota consumption reduced as appropriate. Dead keys (for which the key type has been removed) will be garbage collected immediately. Revoked and expired keys will hang around for a number of seconds, as set in /proc/sys/kernel/keys/gc_delay before being automatically removed. The default is 5 minutes. Signed-off-by: David Howells Signed-off-by: James Morris --- include/linux/key.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/key.h b/include/linux/key.h index e544f466d69..33e0165de10 100644 --- a/include/linux/key.h +++ b/include/linux/key.h @@ -129,7 +129,10 @@ struct key { struct rw_semaphore sem; /* change vs change sem */ struct key_user *user; /* owner of this key */ void *security; /* security data for this key */ - time_t expiry; /* time at which key expires (or 0) */ + union { + time_t expiry; /* time at which key expires (or 0) */ + time_t revoked_at; /* time at which key was revoked */ + }; uid_t uid; gid_t gid; key_perm_t perm; /* access permissions */ -- cgit v1.2.3 From ee18d64c1f632043a02e6f5ba5e045bb26a5465f Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 2 Sep 2009 09:14:21 +0100 Subject: KEYS: Add a keyctl to install a process's session keyring on its parent [try #6] Add a keyctl to install a process's session keyring onto its parent. This replaces the parent's session keyring. Because the COW credential code does not permit one process to change another process's credentials directly, the change is deferred until userspace next starts executing again. Normally this will be after a wait*() syscall. To support this, three new security hooks have been provided: cred_alloc_blank() to allocate unset security creds, cred_transfer() to fill in the blank security creds and key_session_to_parent() - which asks the LSM if the process may replace its parent's session keyring. The replacement may only happen if the process has the same ownership details as its parent, and the process has LINK permission on the session keyring, and the session keyring is owned by the process, and the LSM permits it. Note that this requires alteration to each architecture's notify_resume path. This has been done for all arches barring blackfin, m68k* and xtensa, all of which need assembly alteration to support TIF_NOTIFY_RESUME. This allows the replacement to be performed at the point the parent process resumes userspace execution. This allows the userspace AFS pioctl emulation to fully emulate newpag() and the VIOCSETTOK and VIOCSETTOK2 pioctls, all of which require the ability to alter the parent process's PAG membership. However, since kAFS doesn't use PAGs per se, but rather dumps the keys into the session keyring, the session keyring of the parent must be replaced if, for example, VIOCSETTOK is passed the newpag flag. This can be tested with the following program: #include #include #include #define KEYCTL_SESSION_TO_PARENT 18 #define OSERROR(X, S) do { if ((long)(X) == -1) { perror(S); exit(1); } } while(0) int main(int argc, char **argv) { key_serial_t keyring, key; long ret; keyring = keyctl_join_session_keyring(argv[1]); OSERROR(keyring, "keyctl_join_session_keyring"); key = add_key("user", "a", "b", 1, keyring); OSERROR(key, "add_key"); ret = keyctl(KEYCTL_SESSION_TO_PARENT); OSERROR(ret, "KEYCTL_SESSION_TO_PARENT"); return 0; } Compiled and linked with -lkeyutils, you should see something like: [dhowells@andromeda ~]$ keyctl show Session Keyring -3 --alswrv 4043 4043 keyring: _ses 355907932 --alswrv 4043 -1 \_ keyring: _uid.4043 [dhowells@andromeda ~]$ /tmp/newpag [dhowells@andromeda ~]$ keyctl show Session Keyring -3 --alswrv 4043 4043 keyring: _ses 1055658746 --alswrv 4043 4043 \_ user: a [dhowells@andromeda ~]$ /tmp/newpag hello [dhowells@andromeda ~]$ keyctl show Session Keyring -3 --alswrv 4043 4043 keyring: hello 340417692 --alswrv 4043 4043 \_ user: a Where the test program creates a new session keyring, sticks a user key named 'a' into it and then installs it on its parent. Signed-off-by: David Howells Signed-off-by: James Morris --- include/linux/cred.h | 1 + include/linux/key.h | 3 +++ include/linux/keyctl.h | 1 + include/linux/sched.h | 1 + include/linux/security.h | 38 ++++++++++++++++++++++++++++++++++++++ 5 files changed, 44 insertions(+) (limited to 'include/linux') diff --git a/include/linux/cred.h b/include/linux/cred.h index 85439abdbc8..24520a539c6 100644 --- a/include/linux/cred.h +++ b/include/linux/cred.h @@ -152,6 +152,7 @@ struct cred { extern void __put_cred(struct cred *); extern void exit_creds(struct task_struct *); extern int copy_creds(struct task_struct *, unsigned long); +extern struct cred *cred_alloc_blank(void); extern struct cred *prepare_creds(void); extern struct cred *prepare_exec_creds(void); extern struct cred *prepare_usermodehelper_creds(void); diff --git a/include/linux/key.h b/include/linux/key.h index 33e0165de10..cd50dfa1d4c 100644 --- a/include/linux/key.h +++ b/include/linux/key.h @@ -278,6 +278,8 @@ static inline key_serial_t key_serial(struct key *key) extern ctl_table key_sysctls[]; #endif +extern void key_replace_session_keyring(void); + /* * the userspace interface */ @@ -300,6 +302,7 @@ extern void key_init(void); #define key_fsuid_changed(t) do { } while(0) #define key_fsgid_changed(t) do { } while(0) #define key_init() do { } while(0) +#define key_replace_session_keyring() do { } while(0) #endif /* CONFIG_KEYS */ #endif /* __KERNEL__ */ diff --git a/include/linux/keyctl.h b/include/linux/keyctl.h index c0688eb7209..bd383f1944f 100644 --- a/include/linux/keyctl.h +++ b/include/linux/keyctl.h @@ -52,5 +52,6 @@ #define KEYCTL_SET_TIMEOUT 15 /* set key timeout */ #define KEYCTL_ASSUME_AUTHORITY 16 /* assume request_key() authorisation */ #define KEYCTL_GET_SECURITY 17 /* get key security label */ +#define KEYCTL_SESSION_TO_PARENT 18 /* apply session keyring to parent process */ #endif /* _LINUX_KEYCTL_H */ diff --git a/include/linux/sched.h b/include/linux/sched.h index 5c7ce13c169..9304027673b 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1292,6 +1292,7 @@ struct task_struct { struct mutex cred_guard_mutex; /* guard against foreign influences on * credential calculations * (notably. ptrace) */ + struct cred *replacement_session_keyring; /* for KEYCTL_SESSION_TO_PARENT */ char comm[TASK_COMM_LEN]; /* executable name excluding path - access with [gs]et_task_comm (which lock diff --git a/include/linux/security.h b/include/linux/security.h index 40ba39ea68c..97de3fe3dd0 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -653,6 +653,11 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * manual page for definitions of the @clone_flags. * @clone_flags contains the flags indicating what should be shared. * Return 0 if permission is granted. + * @cred_alloc_blank: + * @cred points to the credentials. + * @gfp indicates the atomicity of any memory allocations. + * Only allocate sufficient memory and attach to @cred such that + * cred_transfer() will not get ENOMEM. * @cred_free: * @cred points to the credentials. * Deallocate and clear the cred->security field in a set of credentials. @@ -665,6 +670,10 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * @new points to the new credentials. * @old points to the original credentials. * Install a new set of credentials. + * @cred_transfer: + * @new points to the new credentials. + * @old points to the original credentials. + * Transfer data from original creds to new creds * @kernel_act_as: * Set the credentials for a kernel service to act as (subjective context). * @new points to the credentials to be modified. @@ -1103,6 +1112,13 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * Return the length of the string (including terminating NUL) or -ve if * an error. * May also return 0 (and a NULL buffer pointer) if there is no label. + * @key_session_to_parent: + * Forcibly assign the session keyring from a process to its parent + * process. + * @cred: Pointer to process's credentials + * @parent_cred: Pointer to parent process's credentials + * @keyring: Proposed new session keyring + * Return 0 if permission is granted, -ve error otherwise. * * Security hooks affecting all System V IPC operations. * @@ -1498,10 +1514,12 @@ struct security_operations { int (*dentry_open) (struct file *file, const struct cred *cred); int (*task_create) (unsigned long clone_flags); + int (*cred_alloc_blank) (struct cred *cred, gfp_t gfp); void (*cred_free) (struct cred *cred); int (*cred_prepare)(struct cred *new, const struct cred *old, gfp_t gfp); void (*cred_commit)(struct cred *new, const struct cred *old); + void (*cred_transfer)(struct cred *new, const struct cred *old); int (*kernel_act_as)(struct cred *new, u32 secid); int (*kernel_create_files_as)(struct cred *new, struct inode *inode); int (*kernel_module_request)(void); @@ -1639,6 +1657,9 @@ struct security_operations { const struct cred *cred, key_perm_t perm); int (*key_getsecurity)(struct key *key, char **_buffer); + int (*key_session_to_parent)(const struct cred *cred, + const struct cred *parent_cred, + struct key *key); #endif /* CONFIG_KEYS */ #ifdef CONFIG_AUDIT @@ -1755,9 +1776,11 @@ int security_file_send_sigiotask(struct task_struct *tsk, int security_file_receive(struct file *file); int security_dentry_open(struct file *file, const struct cred *cred); int security_task_create(unsigned long clone_flags); +int security_cred_alloc_blank(struct cred *cred, gfp_t gfp); void security_cred_free(struct cred *cred); int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp); void security_commit_creds(struct cred *new, const struct cred *old); +void security_transfer_creds(struct cred *new, const struct cred *old); int security_kernel_act_as(struct cred *new, u32 secid); int security_kernel_create_files_as(struct cred *new, struct inode *inode); int security_kernel_module_request(void); @@ -2286,6 +2309,9 @@ static inline int security_task_create(unsigned long clone_flags) return 0; } +static inline void security_cred_alloc_blank(struct cred *cred, gfp_t gfp) +{ } + static inline void security_cred_free(struct cred *cred) { } @@ -2301,6 +2327,11 @@ static inline void security_commit_creds(struct cred *new, { } +static inline void security_transfer_creds(struct cred *new, + const struct cred *old) +{ +} + static inline int security_kernel_act_as(struct cred *cred, u32 secid) { return 0; @@ -2923,6 +2954,9 @@ void security_key_free(struct key *key); int security_key_permission(key_ref_t key_ref, const struct cred *cred, key_perm_t perm); int security_key_getsecurity(struct key *key, char **_buffer); +int security_key_session_to_parent(const struct cred *cred, + const struct cred *parent_cred, + struct key *key); #else @@ -2950,6 +2984,10 @@ static inline int security_key_getsecurity(struct key *key, char **_buffer) return 0; } +static inline int security_key_session_to_parent(const struct cred *cred, + const struct cred *parent_cred, + struct key *key); + #endif #endif /* CONFIG_KEYS */ -- cgit v1.2.3 From 945af7c3289c26c9070d6b1bf3ca759d36643e0b Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 4 Sep 2009 09:19:48 +0100 Subject: KEYS: security_cred_alloc_blank() should return int under all circumstances Make security_cred_alloc_blank() return int, not void, when CONFIG_SECURITY=n. Signed-off-by: David Howells Signed-off-by: James Morris --- include/linux/security.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/security.h b/include/linux/security.h index 97de3fe3dd0..f4eb32d5b89 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -2309,8 +2309,10 @@ static inline int security_task_create(unsigned long clone_flags) return 0; } -static inline void security_cred_alloc_blank(struct cred *cred, gfp_t gfp) -{ } +static inline int security_cred_alloc_blank(struct cred *cred, gfp_t gfp) +{ + return 0; +} static inline void security_cred_free(struct cred *cred) { } -- cgit v1.2.3 From be1d6a5f55b30042c57bdfbe7cb4761ed081def0 Mon Sep 17 00:00:00 2001 From: David Howells Date: Mon, 7 Sep 2009 13:24:17 +0100 Subject: KEYS: Fix default security_session_to_parent() Fix the default security_session_to_parent() in linux/security.h to have a body. Signed-off-by: David Howells Signed-off-by: James Morris --- include/linux/security.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/security.h b/include/linux/security.h index f4eb32d5b89..10a09257952 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -2988,7 +2988,10 @@ static inline int security_key_getsecurity(struct key *key, char **_buffer) static inline int security_key_session_to_parent(const struct cred *cred, const struct cred *parent_cred, - struct key *key); + struct key *key) +{ + return 0; +} #endif #endif /* CONFIG_KEYS */ -- cgit v1.2.3 From b1ab7e4b2a88d3ac13771463be8f302ce1616cfc Mon Sep 17 00:00:00 2001 From: "David P. Quigley" Date: Thu, 3 Sep 2009 14:25:56 -0400 Subject: VFS: Factor out part of vfs_setxattr so it can be called from the SELinux hook for inode_setsecctx. This factors out the part of the vfs_setxattr function that performs the setting of the xattr and its notification. This is needed so the SELinux implementation of inode_setsecctx can handle the setting of the xattr while maintaining the proper separation of layers. Signed-off-by: David P. Quigley Acked-by: Serge Hallyn Signed-off-by: James Morris --- include/linux/xattr.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/xattr.h b/include/linux/xattr.h index d131e352cfe..5c84af8c5f6 100644 --- a/include/linux/xattr.h +++ b/include/linux/xattr.h @@ -49,6 +49,7 @@ struct xattr_handler { ssize_t xattr_getsecurity(struct inode *, const char *, void *, size_t); ssize_t vfs_getxattr(struct dentry *, const char *, void *, size_t); ssize_t vfs_listxattr(struct dentry *d, char *list, size_t size); +int __vfs_setxattr_noperm(struct dentry *, const char *, const void *, size_t, int); int vfs_setxattr(struct dentry *, const char *, const void *, size_t, int); int vfs_removexattr(struct dentry *, const char *); -- cgit v1.2.3 From 1ee65e37e904b959c24404139f5752edc66319d5 Mon Sep 17 00:00:00 2001 From: "David P. Quigley" Date: Thu, 3 Sep 2009 14:25:57 -0400 Subject: LSM/SELinux: inode_{get,set,notify}secctx hooks to access LSM security context information. This patch introduces three new hooks. The inode_getsecctx hook is used to get all relevant information from an LSM about an inode. The inode_setsecctx is used to set both the in-core and on-disk state for the inode based on a context derived from inode_getsecctx.The final hook inode_notifysecctx will notify the LSM of a change for the in-core state of the inode in question. These hooks are for use in the labeled NFS code and addresses concerns of how to set security on an inode in a multi-xattr LSM. For historical reasons Stephen Smalley's explanation of the reason for these hooks is pasted below. Quote Stephen Smalley inode_setsecctx: Change the security context of an inode. Updates the in core security context managed by the security module and invokes the fs code as needed (via __vfs_setxattr_noperm) to update any backing xattrs that represent the context. Example usage: NFS server invokes this hook to change the security context in its incore inode and on the backing file system to a value provided by the client on a SETATTR operation. inode_notifysecctx: Notify the security module of what the security context of an inode should be. Initializes the incore security context managed by the security module for this inode. Example usage: NFS client invokes this hook to initialize the security context in its incore inode to the value provided by the server for the file when the server returned the file's attributes to the client. Signed-off-by: David P. Quigley Acked-by: Serge Hallyn Signed-off-by: James Morris --- include/linux/security.h | 55 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) (limited to 'include/linux') diff --git a/include/linux/security.h b/include/linux/security.h index 10a09257952..d050b66ab9e 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -1382,6 +1382,41 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * audit_rule_init. * @rule contains the allocated rule * + * @inode_notifysecctx: + * Notify the security module of what the security context of an inode + * should be. Initializes the incore security context managed by the + * security module for this inode. Example usage: NFS client invokes + * this hook to initialize the security context in its incore inode to the + * value provided by the server for the file when the server returned the + * file's attributes to the client. + * + * Must be called with inode->i_mutex locked. + * + * @inode we wish to set the security context of. + * @ctx contains the string which we wish to set in the inode. + * @ctxlen contains the length of @ctx. + * + * @inode_setsecctx: + * Change the security context of an inode. Updates the + * incore security context managed by the security module and invokes the + * fs code as needed (via __vfs_setxattr_noperm) to update any backing + * xattrs that represent the context. Example usage: NFS server invokes + * this hook to change the security context in its incore inode and on the + * backing filesystem to a value provided by the client on a SETATTR + * operation. + * + * Must be called with inode->i_mutex locked. + * + * @dentry contains the inode we wish to set the security context of. + * @ctx contains the string which we wish to set in the inode. + * @ctxlen contains the length of @ctx. + * + * @inode_getsecctx: + * Returns a string containing all relavent security context information + * + * @inode we wish to set the security context of. + * @ctx is a pointer in which to place the allocated security context. + * @ctxlen points to the place to put the length of @ctx. * This is the main security structure. */ struct security_operations { @@ -1590,6 +1625,10 @@ struct security_operations { int (*secctx_to_secid) (const char *secdata, u32 seclen, u32 *secid); void (*release_secctx) (char *secdata, u32 seclen); + int (*inode_notifysecctx)(struct inode *inode, void *ctx, u32 ctxlen); + int (*inode_setsecctx)(struct dentry *dentry, void *ctx, u32 ctxlen); + int (*inode_getsecctx)(struct inode *inode, void **ctx, u32 *ctxlen); + #ifdef CONFIG_SECURITY_NETWORK int (*unix_stream_connect) (struct socket *sock, struct socket *other, struct sock *newsk); @@ -1839,6 +1878,9 @@ int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen); int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid); void security_release_secctx(char *secdata, u32 seclen); +int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen); +int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen); +int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen); #else /* CONFIG_SECURITY */ struct security_mnt_opts { }; @@ -2595,6 +2637,19 @@ static inline int security_secctx_to_secid(const char *secdata, static inline void security_release_secctx(char *secdata, u32 seclen) { } + +static inline int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) +{ + return -EOPNOTSUPP; +} +static inline int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) +{ + return -EOPNOTSUPP; +} +static inline int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) +{ + return -EOPNOTSUPP; +} #endif /* CONFIG_SECURITY */ #ifdef CONFIG_SECURITY_NETWORK -- cgit v1.2.3